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UNiaD STATES PATENT (hriricia.4

E. H. HAVLEY, OF' SIGNAL CORPS, ARMY OF THE POTOMAC.

CRYPTOGRAPHIC ALPHABET.

Specification forming part of Letters Patent No. 48,681, dated July ll, 1865.

To all whom t may concern Be it known that I, E. H. HAWLEY, ofthe Signal Corps, Army ofthe Potomac, have invented a new and Improved Cryptographical Alphabet; and I do hereby declare that the following is ai'ull, clear, and exact description thereof, which will enable others skilled in the art to make and use the saine, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l shows my improved cryptographical alphabet with its tablets arranged for giving an example of its mode ot' operation. Fig. 2 shows the number of tablet s andthe arrangement ofthe letters thereon. Fig. 3 shows the alphabet as closed when not in use.

The object of my invention is to so construct a cryptographical alphabet that the different letter-tablets may be variously adjusted with relation to each other as dictated by a new keyword,and the signification ot' the different key letters or characters so changed thereby that even an expert who thoroughly understands the system and apparatus cannot decipher a dispatch without lrst possessing the key-word which dictates the arrangementof the tablets. I construct my alphabet as follows: Thirty tablets are provided by taking thirty strips of brass or other suitable material and placing thereon two columns of letters, &c., the lel'thand column in all of the tablets heilig the twentysix letters of the English alphabet arranged in alphabetical order, and below the last letter of the alphabet the character 85, and next below a figure 5, which when used represents the end of a word, and below the figure 5 are placed the two parts ofwords ing7and tion, makingthe left-hand column ofeach tablet consist in thirty characters, and these thirty characters having the same respective arrangementon each of the thirty tablets. uIn the righthand column of characters on each tablet the same characters are employed as in the left-hand column,butin theirarrangementtheyaretransposed, so that the rst right-hand letter of the rst tablet is A, the next on the second tablet is 13, and the next C, and so on through the thirty characters and the thirty righthand columns of the thirty tablets, the first character of the right-hand column on the thirtieth tablet being tioni In the lower or blank end of each tablet a hole, a, (see tablets l, 2, and 3, Fig. 2,) is made, and they are pivoted together between a pair of guards or covers, b b, Fig. l, by a pivot, c, the pivot being secured in place in an adjustable manner by a n u t, d, or by other suitable means.

To illustrate, its operation is as fellows: It the communicating parties have agreed upon the word Grant as the key-word, then the pivot c is withdrawn, and the tablet which has the letter G at the top of the right-hand column is first selected, (tablet No. 7,) and next the tablet whose right-hand column begins with lt, (tablet No. 18,) and 'then the other three tablets whose right-hand columns begin with A, N, and T are successively picked out. The five tablets whose right-hand columns are headed with the five letters which spell the key-word are then placed on the pivot c in the same order as the letters in the keyword, GRANT, as shown by` Fig. 1. The rest of the tablets are then slipped onto the pivot and turned back into the palm of the hand and serve as a handle. The pivot cis then secured in place by screwing on the nut d, and the alphabet is ready for reading a communication or for dictating one. New, if the dispatch to be written should be We have two days rations, the mode of writing itwould be as follows: The tablet (No. 7) which represents the first letter of the key-word is first referred to, and running down the right-hand column of characters until the first letter of the dispatch, W, is found, the operator then takes the opposite letter in the left-hand column of characters, which is Q5 and writes down Q for the first letter of the dispatch, and then referring to the next tablet, (No. 18,) he follows down the right-hand column to the letter E, and finding R opposite in the left-hand column, writes down It as the second letter of the dispatch; then taking the third tablet, (No. 1,) and finding in the righthand column the gure 5, (which denotes the end of aword,) and,as is found in this case, the same character is found opposite, the figure 5 is then written down. The next tablet in order is referred to, (which is tablet N o. 14,) and H 7 is found in the right-hand column, and in the written dispatch will be represented by YJ The next tablet (No. 20) is in like /rnanner then referred to, and L is Writtenv down to represent A The operator then begins again with the rst tablet, (No. 7,) and finds a representative for the next let-ter of the dispatch, and so on continues to use the ive tablets in regular rotation until the dispatch is Written, when the written dispatch, -We have two da) s rations,77 will appear thus QR YLPRGDIKDR-FMKRRA GNF, and when the receiver reads the same, by using the key-Word GRANT/by which it Was dictated, it will appear thus: QRSYLPRGDIKDRF- MKRRAGNF We have two days rations. When a key-Word is to be used in which one or more than one of the letters are repeated-for instance, it' the key-word MEADE were used-in that case ihe letter E would be repeated, and there is but one tablet (No.5) which has the letter E at the head ot' the righthand column, and the key-Word MEADE would demand two. Provision is made for this emergency by having eXtra tablets ofthose that are most frequently usedsuch as begin with E, A, O, I, Ste-printed upon the backs of those tablets that are little'used-such as Q, V, Z, &c.-and by turning them they may be used as duplicates of the letters most frequently used, and thereby admit of using keywords in which one or lnoreletters are repeated; but I do not confine myself toa given number of tablets, as more that thirty may be used, if desirable.

It will be seen that in a written dispatch there are no gaps or pauses between Words, and also that one and the samefcharacter in this mode may' point out several different letters, or that different characters at different points of the dispatch point ont the same letterfor instance,in the dispatch given the letter R represents E in the WordWE, E represents A in the word DAYS, and R represents the letter A in the Word RATIONS-so that even in a single dispatch no letter of the dispatch is represented by any fixed character. It so happens in the dispatch given that the iirst two pauses, or-

the ends of words, are indicated by the true character, 5; but it will be seen that a little farther on the pauses are denoted by the letter K, and still farther on that the character 5 is employed to represent thefletter 0 in the Word RATIONS, thus avoiding any fixed ground for unauthorized deciphering in those directions, and throwing such decipherer back upon the chance ot' hitting upon the keyword at random-Which would be only one chance in millions, as many millions of keywords may be used by using sentences after the vocabulary ot' words has been exhausted, making a labyrinth hopelessly intricate for the unadvised or unauthorized d'ecipherer; but, at

the same time, with the possession of the keyword the process ot' deciph-ering a dispatch is simple and rapid.

I claim as new and desire to secure by Letters Patent- A cryptographical alphabet arranged substantiallyY in the manner and i'or therpurpose specified.

EDWIN H. HAWLEY.

Witnesses M. M. LIVINGsToN, F. A. MosLEY. 

